Rock-drill



M. A. KNAPP.

ROCK DRILL.

' APPLICATION man sEPT.5. 191|.

Patented Ang. 22, 1916.

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M. A. KNAPP.

ROCK DRILL.

APPLlcATloN man sEPLS. 191|.V

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ROCK DRILL.

FFIQE.

MOSES ARTHUR KNAPP, OF OAKLAND, CALIFORNIA.

ROCK-DRILL.

Application filed September 5, 1911.

To all LU/0m t may concern:

Be it known that I, MOSES ARTHUR KNAPP, a citizen of the United States,and a resident of Oakland, in the county of Alameda and State ofCalifornia, have invented certain new and useful Improvements inRock-Drills, of which the following is a specification.

The invention relates to rock drills and especially to rock drills ofthe hammer type which are operated by a series of sharp percussive blowsfrom a hammer.

The object of the invention is to provide a rock drill for drilling longcylindrical holes from confined spaces in underground workings by meansof rapid cutting percussive drilling machines.

A further object of the invention is to provide an improved means forrotating the drill bit as it passes through the material being cut.

Another object of the invention is to lprovide means for conveyingwater, or water and compressed air to the face of the drill bit, toclear the hole and remove the material as it is cut by the drill bit.

Another object of the invention is to provide a drilling apparatus whichwill cut deep, straight cylindrical holes in rock without diminishingthe size of the hole with increasing depth.

This drill possesses other advantageous features, which, with theforegoing will be set forth at length in the following description,where I shall outline in full, that form of embodiment of the inventionwhich I have selected for illustration in the drawings accompanying andforming part of the present. specification. The novelty of the inventionwill be included in the claims succeeding said description. From this itwill be apparent that I- do not restrict myself to the showing made bysuch drawings and descriptions as I may adopt many variations within thescope of my invention as eX- pressed in said claims.

My invention may be briefly stated to consist in a drilling device inwhich the impact of a hammer of the percussion type, operating to applya series of blows in rapid succession is transferred to the drill bitthrough a series of rods arranged between the hammer and the drill bit,so that the maximum blow is transmitted t0 the drill bit, The

Specification of Letters Fatent.

Patented Aug. 22, 1916.

Serial No. 647,506.

rods are generally alined by means of a tube provided on its inner endwith means for detachably connecting the drill bit thereto, so that arotation of the tube causes a similar rotation of the drill bit. Meansare also provided for rotating the tube either by hand or power,whichever is the most desirable under the circumstances of operation.Provision is also made for introducing a stream of water into the outerend of the tube, and for causing this water to pass through the drillbit, and to its cutting face. I also employ a novel drill bitparticularly adapted for use with' the drilling apparatus which drills astraight hole of constant diameter.

Referring to the drawings: Figure 1 is an elevation, partly in sectionof a-power operated drilling machine provided with means for introducingwater into the tube, means for rotating the tube, and means foradvancing the tube as the drill bit penetrates the rock, the machinebeing arranged in position for drilling a horizontal hole. Fig. 2 is across section through the drilling machine taken on the line -:c Fig. 1.Fig. 3 is a longitudinal section through the power operated device forrotating the tube, and for moving it longitudinally. Fig. 4: is a crosssection through the power operated mechanism shown in Fig. 8. Fig. 5 isa longitudinal sectional detail of an end of the mechanism for advancingthe tube into the hole. Fig. 6 is a longitudinal section through thedrilling machine showing the tube and one of the rods in position. Figs.7 and 8 are longitudinal sections through the tube showing the sameforward in sections and having the rods arranged therein, the rods inthe two figures being of dierent lengths. Fig. 9 is a section throughthe inner end of the tube and drill bit showing the passagetherethrough. Fig. 10 is a view of the end of the tube and the drillbit, showing the method of detachably connecting the two. Fig. 11 is adetail of the end of one of the sections forming the tube, showing themeans of connecting the sections together and of supporting the impactrods centrally therein. Fig. 12 is a detail of the outer end of thedrill bit showing the means employed for causing the water surroundingthe rods to pass through the drill bit. Figs. 13 to 19 inclusive arecross sec- 60 energy at each contact of the series.

tions taken through various parts of the drilling machine, the tube andthe drill bit. Fig. 13 is taken on line zr-a, Fig. 6; Fig. 14 online b-,Fig. 6; Fig. 15 on line @-0,

Fig. 6; Fig. 16 on the line cZ-Z, Fig. 6; Fig.

17 on line e-e, Fig. 12; Fig. 18 on line f-', Fig. and Fig. 19 on theline g-g Fig. 10. Fig. 20 is a cross section of the drilling machinetaken through the ring' for con- 10 necting the hammer cylinder to theadvancing means. Fig. 21'is a sectional detail of the piston whichoperates to rotate the tube. Fig. 22 is a longitudinal section throughthe drill bit. Fig. 23 is an external view of the drill bit showing thelongitudinal groove therein Fig. 211 is an end view of the drill bit.

The drilling engine may be of any of the various hammer types in generaluse for applying to the drill bit percussional impulses of highfrequency, that shown in the drawings consisting of a cylinder 2 inwhich is arranged the reciprocating hammer 3 which imparts the blows tothe tappet 4. Power 25 is supplied in the form of compressed air orsteam through the conductor 5. Arranged adjacent to the tappet 41 is thechuck 6 which is adapted to receive the tube 7 which extends into thehole being drilled.

A series of separate rods 8 are arranged within the tube, which ispreferably formed of sections coupled together so that, as .the drillbit proceeds into the hole, more sections may be added. lThese rods 8extend from the drill rbit 9 to a position in close relation to thetappet 4, oi` the hammer 3, so that the impact of the tappet or hammeris transferred through the various rods to the drill bit. Hereinafter,wherever the blow of the hammer is referred to, it is to be understoodthat such blow may be transmitted directly to the rod series, or may betransmitted thereto through the tappet.

According to the laws of analytical mechanics, a perfectly elastic bodystriking another of equal weight transmits its kinetic energy to thelatter without loss. My experiments have shown that in the case oftempered steel bars this law is true when the bars are of equal lengthor approximately so. A 20% difference in weight of the bars causes onlya slight loss at impact if the equality of length is preserved. I havefound that a row of steel bars, of approximately equal length andweight, placed production of sound and heat waves. If the rods are notof equal length, the tendency to separation with consequent loss ofenergy will be prevented by the provision of means to hold the rodstogether. Employing this principle in a rock drill, I am enabled tocarry the effect of a blow from the hammer or tappet through theintervening separate rods to the drill bit with but a small loss ofpower and to drill into rock with a hammer drill almost as rapidly atthe end of such composite drill rod of great length as with a shortdrill bit. As far as I am aware, this method of transferring the energyfrom the hammer to the drill bit has never been employed before, so thatit has been impractical to drill long holes with the hammer drill. Atthe present time the drilling of long holes is accomplished by the useof the diamond drill and rotary drills, but the cost of such drilling isalmost prohibitive in or- .dinary work as is evidenced by the slight usemade of them. Y

IVhere the series of rods and drill are of equal length, as is set forthand claimed in Letters Patent No. 1,006,661, granted to me Oct. 24,1911, there is practically no tendency of the rods and drill to separatewhen the percussive impulses are applied through the hammer, and hencethe rapid vibrations will be transferred to the drill with little lossof energy; on the other hand, if there is inequality of length in theseries of rods and bit these elements will separate and there is asevere loss of energy as the result.V In order to overcome this tendencyto separation, an important feature of the present invention comprisesmeans for exerting a constant pressure upon the rods to effectually holdthem and the bit together during the application of the percussionalblows by the hammer.

The length of the rods of the rod series is generally governed by thearea of the confined underground space in which the drilling engine isoperating, and the distance through which the engine may bermoved on itssupport. The length of the sections of tube surrounding the rods is alsogoverned by the same conditions. In practice I have drilled into rock todistances up to one hundred feet using rods of lengths between two feetand three and one-half feet, depending on the conditions of operation.

The rods 8 are supported centrally and alined with the tube 7 by meansof the longitudinal ribs 12 formed on the interior face of the tube.These ribs support the rods so that they are held in perfect alinementwith each other and with the tappet and drill bit, but the contactbetween the rods and the ribs is such that the rods are free to movelengthwise. These ribs terminate in the tube above the drill bit 9, theshank 18 of which is made to lit the interior of the tube, so that thedrill bit is held in a straight line.

As herein shown, (see Figs. 7 and 8), some of the rods 8 are of greaterlength than others so that the elements constituting the rods and bitseries are of unequal length. By inequality of length in this connectionI mean material inequality, and not such inequality as might beconsidered approximate equality.

The drill bit 9 is loosely and detachably connected to the lower sectionof the tube so that it is free to move longitudinally with respectthereto and may be detached therefrom when desired. This is accomplishedby means of a modified bayonet joint 14. The inner end of the tube isprovided with an open clutch l5 which opens onto the end of the tubethrough the slot 16, which is narrower than the cut away portion formingthe clutch. The shank 13 is provided with an elongated lug or boss 17which is adapted to enter through said slot 16 and engage the clutch.

It is essential that the drill bit be rotated during the operationof thedrill so that the cutting edges of the drill bit come in contact withall parts of the rock face.

As the drill is operating the tube is rotated in such direction that thelug is moved in the cut away portion to one side of the slot 16, so thatthe movement of the drill bit is limited to the length of the cut awayportion and under such circumstances cannot become detached from thetube. Should the drill bit become stuck in the drill hole so that itcannot be removed, the tube is rotated in the opposite direction,bringing the lug in line with the slot, so that the tube and rods can bewithdrawn, allowing the drill bit to remain in the hole.

In order to overcome the friction between the rapidly moving drill bitand the side of the aperture as the tube is being rotated, the faces ofthe aperture and lug are inclined in such manner that in the forwardmovement of the drill bit, the lug springs away from the aperture face.This allows all of the energy imparted to the bit to be used in cuttingthe rock and obviates a loss of energy at that point. The pressurebetween the lug and the face of the aperture as the drill is beingrotated in ordinary work is approximately 500 pounds and the energy lostin overcoming the friction due to such pres@ sure would be very large.By forming the side of the aperture at an angle, however, the lug movesout of contact with the face as it begins its forward fnovement and thefriction is avoided.

The tube may be rotated by hand or aower, as desired. When it is to berotated by hand, a handle 18 attached to the sleeve 29 is providedadjacent to the drilling machine. As the tube advances into the hole,the set screw 31 may be loosened and the sleeve 29 clamped on the nextsection 0f the lliquid at the face of the drill tube added. The tube mayalso be rotated by gripping it with a pipe wrench when a handle such as18 is not convenient. I have also provided means for rotating the tubeby power, preferably from the same source as that used to operate thehammer. This mechanism is inclosed in a casing 20 at the forward end ofthe machine and is supplied with power through the conductor 21. A valve23 is employed for cutting off the power supply when desired. Within thecasing is the reciprocatingl piston 24, which operates the bent lever 25pivoted to the side of the casing at 20. Mounted on this lever 25 is aspring held pawl 27 which engages the ratchet 28. This ratchet is shownas formed integral with the sleeve or collar 29 through which the tubeprojects and to which it is clamped by the set screw 31. An oppositelyplaced spring held pawl 32 prevents a reverse rotation of the ratchet.lt is evident that as the piston 24 reciprocates, the pawl 27 acts torotate the sleeve 29. The compressed-air for operating the piston entersthe annular space 106 formed by the shoulder 112 on the piston throughthe passage 105, and moves the piston downward. At the end of thestroke, the port 109 registers with the chamber 106 and allows the airto move through the passage 108 into the chamber 107 which reverses thedirection of motion of the piston. At the end of the upward stroke thepassage 110 registers with the outlet port 111 and allows the air toexhaust. The valve 23 is then opened to allow air to again enter thechamber 106.

Provision is also made for introducing a bit. The upper end of the tube7 is clamped in the chuck 6 which opens into the chamber 34. Water issupplied to this chamber through the inlet pipe 35 to which is attachedthe conductor 36. The water is forced into the chamber under the rquiredpressure by means of the force pump 37 which may be operated by thecompressed air supply. Provision is also made for introducing a quantityof air with the water by connecting the water sup ply conductor 36 withthe air conductor by the conductor 38. A cock 39 is arranged at thispoint of connection to regulate the air supply to the pump 37 and thechamber The tube 7 is clamped in the chuck 6 by means of the clampingring 41 and the set screw 42 and is held in such position that the endthereof is adjacent to the inner end of the chuck. A ledge 43 isprovided on the inner surface of the chuck to seat the tube at theproper place. The last rod of the rod series lies in the tube andprojects from the end thereof so that it is in position to be struck bythe tappet 4 which also lies partly within the chamber 34. To preventleakage from this chamber, the chuck and the tappet are surrounded withpacking 45 which is held confined by the packing rings 46. These packingrings are held apart and pressed against the packing by the spiralspring 47 thereby providing a very eflicient water tight joint.

The water entering chamber 34 passes into the tube 7 between the tubeand the rods and is conveyed to the forward end of the tube. To providemeans for transferring the water from the outside of the rods to theinside of the drill bit, the first rod is provided at its forward endwith an aperture 48 arranged centrally therein and opening on the sideof the rod. The hollow portion is made of the same diameter as the drillshank, which is also made hollow for the purpose of conducting theliquid therethrough. The passage 49 in the drill shank terminates in agroove 51 in the side of the drill bit, and near the upper or rear endof the drill bit head. The groove 51 closed at the rear end extends forthe length of the drill bit head and conveys the liquid to the cuttingface. The liquid carrying the rock cuttings then Hows backward betweenthe tube and the face of the drilled hole and may be collected andexamined to determine the formation through which the drill bit ispassing.

rlhe drill bit which I employ in connection with the rod series is ofnovel construction and is the only bit that l am aware of which willoperate in conjunction with the apparatus of my invention to drill along cylindrical straight hole of equal diameter at all depths.Heretofore, deep holes must necessarily have been drilled smaller at thebottom than at the top, due to the wear on the bit, 'but thisobjectionable feature has been eliminated by the use of the present bit.ln drilling holes with the present apparatus it is essential that thehole be straight and of substantially constant diameter in order toallow the tube surrounding the rods to enter the hole.

The drill bit is preferably formed with a prismatic head to which iswelded the shank which engages the tube. The face of the bit is formedwith an eccentric point 87, which is of substantially conical shape. Theeccentric point cuts into the face of the rock and the edges 88--101-96and 10i?J of the body cut into the sides and preserve the width of thehole. These edges are long and suffer very little wear, even on the sideopposite the eccentric point, although thrown strongly against the sideof the drill hole by the glancing blow of the point. A new drill of thesame size inserted into the hole -when the one being used is worn, willalways advance to the, end of the hole. The face of the eccentric coneshaped point 87 is provided with cutting edges 89--90- 91-92# 93-94--95on that side which is farthest from the axis of the drill. The groove inthe bit for allowing the water to flow to the drillface is arranged onthat side of the drill bit head which is opposite the eccentric point,and which is held against the rock. On account of the eccentricity ofthe forward cutting edges, and the rotation of the drill, the bitglances on the rock face as it strikes, causing the side edges of theprism to strike against all sides of the drill hole. The sloping edgesof the eccentric point do not cut the whole of the end of the drillhole, but leave a small concentric rock shelf which is cut down by theshovel edges 10G- 88, 88-S9, 98-96 and 96-97 on the side of the bitopposite the eccentric point. The effect of the cutting of the side ofthe drill hole by the long side edges of the prismatic head and of thecutting of the rock shelf by the shovel edges is that the drill hole isalways from 9g to fig of an inch larger than the drill bit. The holeremains straight on account of the length of the side edges opposite theeccentric point, their parallelism with the drill axis, and theavoidance of all flare of these edges at their forward ends. This is anovel feature of this bit and practically essential in the drilling ofstraight holes through broken rock formations.

Provision has also been made for advancing the tube into the drill holeas the rock is cut away and for withdrawing theV tube when desired, thesame devices that perform these functions also serving inthe embodimentof the invention herein illustrated, to hold the series of rods and bittogether. Arranged below the hammer cylinder 2 and in close relationthereto is the pressure cylinder 52 in which operates the hollow piston53. The piston 53 is connected to a rod 54, in this instance through thecasing containing the power operated tube rotating mechanism. The rod 54lies adjacent the hammer cylinder 2 and is provided with a series oflugs 55, between any two of which the lug 56 on the rotatable ring 57 onthe hammer cylinder' is adapted to engage. The ring 57 is looselymounted for rotation on the cylinder so that it can be turned to engageor disengage the lug 56 with the rod 54. It is evident that when inengagement a movement of the piston 53 causes a simultaneous movement ofthe cylinder 2 and the tube rotating mechanism, so that the tube ismoved as desired. It will also be evident that the piston 53 will actthrough the rod 54 and cylinder 2 to hold the tappet 4 against the endrod or in such close proximity thereto that the several rods and bitcannot separate. This is a valuable characteristic of the presentimprovements, as it is essential that where the rods and bit, consideredas a series, are not of equality of length some means be provided tohold them against separation. In this connection, the particularinstrumentalities employed for such purpose are not essential to thisinvention, as other means, such as a weight, might be employed ifdesired.

The piston 53 is hollow and is provided with valve connections so thatthe power may be applied from one source to move the piston in eitherdirection. Power is supplied in the form of compressed air through theconductor 21 which also carries the compressed air to the tube rotatingmeans. A four way valve 58 arranged in a block Xed to piston 53 isarranged so that when the compressed air is admitted to one side of thepiston head 59 the other side is in connection with the exhaust 6l. Asshown in the drawings, the air passes down through the pipe 62 to behindthe head 59 thereby moving the piston and tube forward. The air in thecylinder on the other side of the head is exhausting through the port63, the hollow piston 53, the passage 64 and the eX- haust 6l. When thevalve 58 is turned the air current travels in the opposite direction,moving the piston backward and withdrawing the tube. The valve isprovided with a handle 65 on the outside of the piston adjacent the tuberotating means so that the longitudinal movement of the tube may bereadily controlled.

I claim:

l. In a rock drilling apparatus having a drilling engine of the hammertype constructed to apply percussional impulses of high frequency and incombination with a hammer and drill bit, a series of separate alinedcontiguous rods intermediate said hammer and said drill bit, a tubesurrounding said rods and engaging said drill bit and means for rotatingsaid tube and drill bit without subjecting the rods to torsional strain.

2. In a rock drilling apparatus having a drilling engine of the hammertype constructed to apply percussional impulses of high frequency, andin combination with its hammer and drill bit, a series of separate,alined, contiguous rods intermediate said hammer and drill bit, ajointed pipe inclosing said rod series provided with means for detachingthe pipe from the drill including an aperture in the pipe with aninclined face to engage a lug on the drill bit and means for revolvingthe pipe.

3. In a rock drilling apparatus having a drilling engine of the hammertype and in combination with its hammer and drill bit, a series of rodsintermediate said hammer and drill bit, a tube surrounding said rods andthe shank of the drill bit, said tube Ibeing provided near its end withan aperture, and a lug on the shank engaging said aperture, the aperturehaving a bearing surface adapted to bear against the lug when the drillis rotated in one direction, the side of the aperture being inclined tothe aXis of the drill so that a forward movement of the drill bit causesthe lug to move away from said bearing surface.

4. In a rock drilling apparatus, a drill bitv adapted to extend entirelyinto the drill hole, a tube surrounding the shank of said drill bit,means for imparting a blow to said drill bit, means for revolving thetube and means comprising interengaging parts connecting said tube anddrill bit for revolving the drill bit, said parts having inclined facesoperating to minimize the friction between said tube and shank on theforward motion of the drill bit.

5. In a rock drilling apparatus having a drilling engine of the hammertype constructed to apply percussional impulses of high frequency and incombination with its hammer and drill bit, a series of separate rodsalined with and intermediate the hammer and drill bit, a tubesurrounding said rods and the drill bit shank, said tube beingunconnected to said rods, a connection between the tube and the shank tocause a rotation of the drill with the tube, a sleeve attached to thetube at its outer end and power operated means arranged to rotate saidsleeve.

6. In a rock drilling apparatus having a drilling engine of the hammertype constructed to apply percussional impulses of high frequency and incombination with its hammer, a drill bit entirely entered into the drillhole, means for transmitting the blow of the hammer to said drill bitconsisting of a series of separate rods alined with each other andintermediate said hammer and drill bit, means for continuously holdingsaid rods and bit together, a tube surrounding said transmitting meansand means for inroducing a fluid under pressure into said tu e.

7. In a rock drilling apparatus having a drilling engine of the hammertype constructed to apply percussional impulses of high frequency and incombination with its hammer, a drill bit entered entirely into the drillhole, a series of separate rods alined with and intermediate said hammerand drill bit arranged to transmit an energy wave continuously from thehammer to the drill bit, a tube surrounding said rods and the drill bitshank, said tube and drill bit being provided with a continuous passage,means for revolving the tube and drill bit and means for introducing afluid under pressure into such continuous passage.

8. In a rock drilling apparatus having a drilling engine of the hammertype constructed to apply percussional impulses of high frequency and incombination with its hammer and drill bita series of separate rodsalined with and intermediate said hammer and drill bit, means forpressing said rods together, means for continuously holding said rodsand bit together, a tube surrounding said rods and the drill bit shank,the shank of the drill bit and the end of the rod adjacent thereto beingof substantially the same diameter as the interior of said tube andbeing provided with alined passages arranged longitudinally therein andterminating at the side of the rod and in a groove on the side of thedrill bit, and means for conveying a fluid through said tube andpassages.

9. In a rock drilling apparatus having a drilling engine of thevibratory hammer type and in combination with the hammer, a drill bitadapted to be rotated, a tube surrounding the drill bit shank anddetaehably connected thereto, a series of rods for transmitting the blowfrom the hammer to the drill bit arranged intermediate the hammer anddrill bit, means for continuously holding the leading rod of the seriesand the drill bit together during the operation of the hammer, theleading end of the leading rod and the drill bit shank being providedwith central alined passages, the rear end.

of the passage in the rod terminating eccentrically of the rod.

10. In a rock drilling apparatus the combination with a hammerconstructed to apply percussional impulses of high frequency, a drillbit, a series of alined rods between said hammer and bit, said series ofrods and bit being of unequal length, and means for holding the membersof the series together.

11. In a rock drilling apparatus the combination with a hammerconstructed to apply percussional impulses of high frequency, a drillbit, a series of alined rods between said hammer and bit, said series ofrods and bit being of unequal length, and means for holding the membersof the series together by pressure in the rear thereof.

12. In a rock drilling apparatus the combination with a hammerconstructed to apply percussional impulses of high frequency, a drillbit, a series of alined rods between said hammer and bit, said series ofrods and bit being of unequal length, and a power-actuated piston andconnections to hold the members of the series together.

13. In a rock drilling apparatus the combination of a hammer drillingengine, a drill bit, a series of alined rods between said hammer andbit, a tube surrounding said rods and the shank of said drill bit, andpower-actuated means under manual control for causing movement of saidtube in opposite directions for withdrawing it from or inserting it inthe drilled hole, said hammer drilling engine being adapted to beremoved from the apparatus and said power-actuated means being adaptedto move said tube while the drilling engine is removed.

14:. In a rock drilling apparatus, the combination of a hammerconstructed to apply percussional impulses of high frequency, a drillbit, a separate rod between the hammer and bit of unequal length withthe bit, and means for holding the rod pressed against the bit, saidseparate rod being several times as long as the hammer and at leasttwice as long as the drill bit and adapted to transmit by wave actionthe percussional impulses of the hammer blow, said bit and rod beingadapted to be entirely entered into the drill hole.

15. In a rock drilling apparatus having a drilling engine of the hammertype constructed to apply percussional impulses of high frequency and incombination with its hammer, a drill bit entirely entered into the drillhole, means for transmitting the blow of the hammer to said drill bit,consisting of a series of separate rods alined with each other andintermediate the hammer and drill bit, said series of rods and bit beingof unequal length and a tube surrounding said rod series, the tube androds ,being arranged in such position that the blow of the hammer isdelivered to the rods and not to the tube, and means for continuouslyholding said rods and bit together.

16. In a rock drilling apparatus having a drilling engine of the hammertype constructed to apply percussional impulses of high frequency and incombination with its hammer and drill bit, a series of separate alinedrods arranged between the hammer and drill bit shank, a tube surroundingsaid rods and drill bit shank, means for advancing and retiring saidtube and a detachable interlocking connection between the tube and thedrill bit shank, said connection being such that the tube is capable ofconsiderable longitudinal movement independent of the shank.

In testimony whereof I have hereunto set my hand at San Francisco,California, this 31st day of August, 1911.

MOSES ARTHUR KNAPP.

In presence of- H. G. PRosT, R. HEFFERNAN.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents;

Washington, D. (1.

